Troubleshooting

User Guides

Scaling Tectonic AWS clusters

This document explains how to add and remove worker and controller nodes to scale a Tectonic cluster.

Scaling Kubernetes nodes

During installation, Tectonic creates two AWS Auto Scaling Groups (ASGs). The AutoScaleWorker group contains worker nodes, while the AutoScaleController group contains cluster controller nodes. The AutoScaleWorker group can be scaled up or down to add or remove cluster work capacity. The AutoScaleController group can be scaled up to increase control plane availability.

Set the number of members of either group by visiting the AWS EC2 console, under Auto Scaling in the left hand sidebar. Edit the min, max and desired fields for the respective ASG to match capacity needs for workers, or availability demands for more than one controller.

After increasing the number of nodes in either ASG, new nodes will boot and join the cluster within a few minutes.

Scaling down will immediately terminate the node VMs, causing replicated workloads to be restarted on other nodes automatically. The Kubernetes node draining facility is not employed when removing nodes from an ASG.

The Console shows both types of nodes, with the control plane denoted with the label master=true.